welding

[rocko]

if you grind down your welds will it weaken the frame

 

[RobertD]

not if you've welded properly.

You grind welds in order to get rid of the extra material that doesn't sit flat on the metal. To "pretty them up". This isn't a problem if you got plenty of penetration on your weld. If you didn't use enough power, then that is your problem, not the grinding that made the weld weak.